Dihydroxy-disulpho-1:2:2&#39;:1&#39; dinaphthazine and the process of making same



Patented Dec. 29, 1931- UNITED STATES FRITZ STRAUB AND WALTER ANDERAU, 0F BASEL, SWITZERIiAND, ASSIGNORS T0 SOCIETY OF CHEMI CAL INDUSTRY IN BASLE, 0F BASEL, SWITZERLAND DIHYDROXY-DISULPHO-l:2z2:1 :omnrn'rrinzmn AND THE rnocnssflor MAKING SAME No Drawing. Application filed August 26, 1929, Serial No. 388,619, and in Switzerlaind fieptember s, 1928.

The present invention relates to new intermediate products. It comprises the process of making these new products as well as the new products themselves;

It has been found that valuable new intermediate products useful for the production of dyestuffs are obtained by esterifying B-aminonaphthols, which contain one sulfo group, in the hydroxyl group, treating the ester thus obtained with an oxidizing agent in an aqueous solution, and then subjecting the azine-like condensation products thus obtained to a treatment with a saponifying agent.

As particularly valuable has proved to be the azine-like condensation product obtained by subjecting the 2-amino-5-hydroxynaphthalene-7-sulfonic acid to the above described treatment.

For the manufacture of azo-dyestufis these new azine-like condensation products may also be used unsaponified, as esters.

The following example illustrates the invention, the parts being by weight Emamp-Za-QZQ parts of 2-amin0-5-hydroxynaphthalene-7-sulfonic acid aredissolved in 300 parts of caustic soda solution of 30 per cent. strength parts of para-toluenesulfonic chloride are added and the whole is heated to 95 C. until the last-named body has disappeared. After cooling to 18 C. there is added an alkalihypochlorite solution containing 105-130 parts of active chlorine and the temperature is controlled at 20-25 There separates a yellow crystalline body which is isolated. It is apparently the dipara-toluene-sulfonic ester of 5: 5'-dioxy- 7 :7 disulpho 1:2 1' 2 dli -naphthazine. By saponification with 1000 parts of caustic soda solution of 5 per cent. strength at the boiling point the corresponding dihydroxydisulfoazine is obtained. It is soluble in dilute acids and in water to a yellow solution, in alkalies to a red and in concentrated sulfuric acid to a green solution. By addition of a reducing agent to the alkaline solution, there is obtained the dihydroazine which dissolves to an orange solution. The dihydroxysulfoazine from 2-amino-5-naphthol-7-suland 700 parts of water, 224

C. by addition of ice.

.fonic acid combines with a diazo-compound once or twice;

It instead of; the, above-namedr2'r5z7- aminon-aphthol-sulfonic acid there is'used the isomericv 2-amino 8-hydroxy naphtha lene fi sulfonic acid and theoperation is con ducted otherwise as described above, there is obtained 8' '8"- dihydroXy 6 6' disulplio 1:2: 1 '2-dinaphthazine. This compound isvery sparingly soluble in water' to ayel-L low solution, is very sparingly soluble in alkalies to a-redsolution and is-soluble'in concentrated sulfuric "acid to a green solution. In alkali hydrosulfite it yields "(an orange solution of the dihydro azine derivative. p Y

Obviously the OH-group may beesterified by som'e'otlrer esterifying agent'and instead of carrying out the oxidation with hypochloriteit may be carried out with ana other oxidizing agent in an aqueous solution.

What we claim is::. I 1. Process for the manufacture of new intermediate products, consistingin esteritying in the hydroxyl group jB-aminonaphthols of the general fdrmula wherein one y: stands for-an OH-group and the other for an hydrogen atom, one a. for an sO H-group, and theother 2 for anhydrogen atom, and inqwliidh the OH-group and the SOJ-I-g-roup stand in meta-position to each other, then treating the ester with a halogen containing oxidizing agent, and finally subjecting the azine-like condensation products thus obtained to a treatment with a saponifying agent.

2. Process for the manufacture of new intermediate products, consisting in es teritying in the hydroxyl group the 2-amino-5- hydroxynaphthalene -7- sulfonic acid, then treating the ester with a halogen containing oxidizing agent, and finally subjecting the azine-like condensation products thus obtained to a treatment with a saponifying agent.

3. As new products the azine-like condensation products of the general formula wherein one 3 stands for an OH-group, and the other for an hydrogen atom, one 2 for an sO H-group, and the other for an hydrogen atom, and in which the OH-group and the sO H-group stand in meta-position to each other, and in which 1 and z have the same signification as y and z and take up the same positions in the corresponding naphthalene nucleus, which products form yellowish powders which dissolve in water and dilute acids to yellow solutions, in alkalies to red solutions, and in concentrated sulfuric acid to green solutions.

4. As a new product the azine-like condensation product of the formula which forms a yellowish powder, dissolving in water and dilute acids to a yellow solution, in alkalies easily to a red solution,

and in concentrated sulfuric acid to a green solution.

In witness whereof we have hereunto signed our names this 14th day of August FRITZ STRAUB. WALTER ANDERAU. 

